I've used Automatic since 1.x and it's always worked well. I now use 2.x and it is even better. However I only use custom subscriptions with regex.
I find that it is a nice clean app that does what it is supposed to.
I also tried TVShows a few times but always ended up uninstalling it. As it wasn't as powerful (regex) or as nice to use as Automatic.
I've had a couple of issues but it had some thing to do with some other file getting messed up which is extremely common with OSX software at the moment even with major league software. But luckily the support is amazing which prompted me to buy this software in the first place.

After purchasing and using for less than a year, the program no longer works. I installed on a Mac Mini and did not update software or do anything different from when I bought the program. Email sent to support has gone unanswered.
I cannot recommend buying this program. There is an awesome free alternative named "TVShows" that has filled the $20 void that this program's developers left.

Sad to hear people say v2.x doesn't work well. I'm still using v1.x (available free on their website) and it's still rock solid and a wonderful tool. Not quite as easy as the newer version looks to use, but a large part of may automated TV Show workflow (Automatic -> Transmission -> Magic Media Marker -> iTunes/Apple TV).

Good when it works, but for over a month it fails with about 90% of the shows. This has something to do with the RSS source, but the developer is very unresponsive. The support forum is FILLED with complaints "doesn't work", "stopped working", etc and the developer is making vague promises of an update "hopefully" in May.
Great when it works, but the support is unimpressive. I can't recommend it over free alternatives unless there is some support.

I currently have automator doing this very same thing and it is already on your mac. I will try this though as automator has a few quirks that this software may solve and it looks a little easier to set up.